Long-term outcome for prostate cancer using pseudo pulse–dosed rate brachytherapy, external beam radiotherapy, and hormones

Abstract

We report the long-term outcomes of pulse-dose rate (PDR) brachytherapy used in a nonstandard style (pseudo-PDR) with an high-dose rate brachytherapy technique in conjunction with external beam radiotherapy (EBRT) and hormonal manipulation on prostate cancer (PC). We treated 253 patients with Stage T1-T3 N0M0 PC, between December 1999 and March 2006. All patients received neoadjuvant androgen deprivation for a median 6 months. Treatment consisted of three pulses of pseudo-PDR brachytherapy to a median dose of 18Gy with 50.4Gy in 28 fractions of EBRT. At a median 6 years followup, (range, 1-11 years), 5-year overall survival was 92%, and PC-specific survival was 96%. The 5-year biochemical control (biochemical no evidence of disease) by the Phoenix definition for low-, intermediate-, and high-risk groups was 95%, 90%, and 71%, respectively (p<0.00001). At 6 years, the incidence of Radiotherapy Oncology Group Grade 2 and 3 genitourinary toxicity was 1% and 6%; Radiotherapy Oncology Group Grade 2 and 3 gastrointestinal toxicity was 4% and 0%. Erectile preservation at 3 years was 58%. The Phoenix definition best predicted clinical failure with a high specificity (94%). Pseudo-PDR brachytherapy plus EBRT with limited neoadjuvant hormonal manipulation is an effective treatment option in localized PC, with minimal and tolerable morbidity and provides excellent control. This technique of a modified PDR-delivery technique appears as effective as high-dose rate therapy.